What are the diagnostic tests and management strategies for abnormal uterine bleeding in a pregnant woman with diabetes and hypertension?

Abnormal Uterine Bleeding in Pregnancy with Diabetes and Hypertension

In a pregnant woman with diabetes and hypertension presenting with abnormal uterine bleeding, immediately rule out pregnancy complications (placental abruption, threatened miscarriage, ectopic pregnancy) and preeclampsia-related bleeding, as these represent life-threatening emergencies requiring urgent obstetric intervention. 1

Immediate Assessment and Risk Stratification

Critical Initial Evaluation

• Confirm gestational age to determine if bleeding occurs before or after 20 weeks, as this fundamentally changes the differential diagnosis and management approach 1
• Assess hemodynamic stability and signs of hypovolemic shock, as maternal mortality from placental abruption and hemorrhage is significantly elevated in women with hypertension 1
• Evaluate for preeclampsia/eclampsia features: severe headache, visual disturbances, right upper quadrant pain, seizures, as these require immediate delivery 1

High-Risk Context Recognition

This patient has multiple risk factors for preeclampsia (preexisting hypertension and diabetes), which increases risk of placental abruption, the most dangerous cause of bleeding in hypertensive pregnancy 1

Essential Diagnostic Testing

Immediate Laboratory Panel

Order stat laboratory tests including: 1

• Complete blood count with hemoglobin and platelet count to assess for anemia from bleeding and thrombocytopenia suggesting HELLP syndrome 1, 2
• Liver enzymes (AST, ALT, LDH) to detect HELLP syndrome or preeclampsia with hepatic involvement 1, 2
• Serum creatinine, electrolytes, and uric acid to evaluate renal function and preeclampsia severity 1, 2
• Coagulation profile (PT, PTT, fibrinogen) if significant bleeding or concern for DIC 1
• Quantitative β-hCG if early pregnancy (<20 weeks) to assess viability and rule out ectopic pregnancy or molar pregnancy 3

Proteinuria Assessment

• Urine dipstick immediately, followed by urine albumin-to-creatinine ratio (UACR) or protein-to-creatinine ratio (PCR) if dipstick shows ≥1+ protein 1, 2
• UACR >30 mg/mmol (265 mg/g) or PCR >300 mg/24h confirms proteinuria and preeclampsia diagnosis when combined with hypertension after 20 weeks 1

Imaging Studies

Transvaginal ultrasound is the primary imaging modality to: 3, 4

• Confirm intrauterine pregnancy and fetal viability
• Assess placental location and rule out placenta previa
• Evaluate for placental abruption (though ultrasound has limited sensitivity)
• Identify structural uterine causes (fibroids, polyps) if bleeding is not pregnancy-related

Doppler ultrasound of uterine arteries after 20 weeks helps identify women at higher risk of preeclampsia and intrauterine growth retardation 1

Diabetes-Specific Monitoring

• Glucose monitoring (fasting and postprandial) as diabetic ketoacidosis can complicate pregnancy and bleeding episodes 1
• Hemoglobin A1C if not recently checked, though target in pregnancy is <6% if achievable without hypoglycemia 1

Blood Pressure Management During Evaluation

Critical Hypertension Thresholds

Blood pressure ≥160/110 mmHg constitutes a hypertensive emergency in pregnancy requiring hospitalization and immediate treatment to prevent maternal stroke 1

Acute Blood Pressure Control Options

For severe hypertension (≥160/110 mmHg): 1

• Intravenous labetalol (first-line)
• Oral methyldopa or oral nifedipine (immediate-release)
• Avoid intravenous hydralazine as it is associated with more perinatal adverse effects than other agents 1

Blood Pressure Monitoring

Use validated devices specifically for pregnancy and preeclampsia (manual auscultatory or automated upper-arm cuff validated for pregnancy) 1

Management Algorithm Based on Gestational Age

Before 20 Weeks Gestation

Primary concerns are miscarriage, ectopic pregnancy, or molar pregnancy: 3

• Serial β-hCG levels to assess pregnancy viability
• Transvaginal ultrasound to confirm intrauterine location and viability
• If ectopic pregnancy confirmed, immediate surgical or medical management required as this is life-threatening 3

After 20 Weeks Gestation

Primary concerns are placental abruption, placenta previa, and preeclampsia-related complications: 1

If preeclampsia with severe features is confirmed (BP ≥160/110, thrombocytopenia <100,000, liver enzymes >2x normal, pulmonary edema, new-onset headache/visual symptoms): 1

• Immediate obstetric consultation for delivery planning
• Magnesium sulfate for seizure prophylaxis
• Corticosteroids if <34 weeks for fetal lung maturity

If placental abruption suspected (painful bleeding, uterine tenderness, fetal distress): 1

• Emergency cesarean delivery is often required
• Prepare for massive transfusion protocol

Ongoing Monitoring Requirements

Frequency of Laboratory Monitoring

For women with abnormal baseline values or preeclampsia: 1, 2

• Repeat hemoglobin, platelets, creatinine, and liver enzymes the day after initial presentation
• Continue minimum twice-weekly blood tests with more frequent testing if clinical deterioration 2

Fetal Monitoring

• Continuous fetal heart rate monitoring if viable gestation and acute bleeding
• Serial growth ultrasounds every 2-4 weeks if chronic bleeding or preeclampsia, as intrauterine growth restriction is common 1

Critical Pitfalls to Avoid

• Never assume bleeding is benign in a hypertensive pregnant patient – placental abruption can be catastrophic and occurs more frequently with hypertension 1
• Do not delay delivery for severe preeclampsia/eclampsia – maternal and fetal mortality increase significantly with delayed intervention 1
• Do not use uric acid levels alone to determine delivery timing, though elevated levels correlate with worse outcomes 1, 2
• Avoid atenolol during pregnancy as it is associated with fetal growth retardation related to treatment duration 1
• Do not restrict salt or recommend weight loss during pregnancy even in obese women, as this may reduce neonatal weight 1

Multidisciplinary Coordination

Immediate consultation required with: 1

• Maternal-fetal medicine specialist for high-risk pregnancy management
• Endocrinologist for diabetes optimization during acute illness 1
• Anesthesiology if delivery anticipated, given hypertension and potential for emergency cesarean